This invention relates to medical methods and apparatus, and more particularly to methods and apparatus for installing a tubular graft in a patient for such purposes as bypassing an occlusion or narrowing in the patient""s tubular body structure.
The invention is applicable to making anastomotic connections between all body conduits. For example, the invention also has application for attaching coronary artery bypass grafts. Specifically, connection methods and apparatus are provided for attaching the graft ends to the coronary artery and the aortic artery. In the case of the internal mammary artery, connection is required at the coronary artery only.
Conventional coronary artery bypass grafting requires the heart and associated vessels to be accessed through the center of the chest by splitting the sternum (e.g., median sternotomy) or through the side by separating the ribs (e.g., thoracotomy). The heart is typically stopped during this process, and the patient is placed on cardiopulmonary bypass. These procedural steps are typically performed in order to allow the physician to safely and precisely sew the grafts with sutures to the exposed arteries as deemed necessary. However, this procedure may involve risks to the patient attributable to the magnitude of the incision required and the procedure of stopping the heart, which allow the physician the access to stitch on a non-beating heart, i.e., xe2x80x9cstaticxe2x80x9d stitching. This procedure may also be associated with various complications, including stroke, heart block, and long patient recovery times. Another factor is the considerable operation time involved due to the criticality of individual hand sewing of each graft end required by the suture process. The precision with which the grafts are sewn may influence the ultimate patency term for the graft.
Typical prior art procedures have been described by Heartport, for example, which attempts to connect vessels through ports inserted between the ribs but also requires the heart to be stopped and the grafts be sewn in place. Cardiothoracic Systems describes a procedure wherein the heart is allowed to beat, but full access to the heart is required as well as hand sewing of the graft segments to the beating heart. Other procedures describe the use of robots and automated mechanical assist devices to complete a sewn anastomosis on beating hearts or through small incisions.
It is thus an advantage of the current invention to overcome some of these difficulties associated with cardiac surgery.
It is an advantage of the invention to eliminate the need to stop the heart.
It is a further advantage of the invention to reduce significantly the size of the incision and to reduce the exposure of the heart and aorta necessary to perform the surgery.
It is still a further advantage of the invention to reduce the time necessary to perform the anastomosis procedure by eliminating the time-consuming task of manually suturing the vessels together.
It is also an advantage of the invention to provide an improved and consistent anastomosis result, without the reliance on the technique and skill of the physician.
These and other advantages of the invention are accomplished in accordance with the principles of the invention by providing an apparatus and methods for use in making an anastomotic connection between two tubular body fluid conduits in a patient, the connector being configured for attachment to the first and second tubular fluid conduits. In one embodiment of the invention, one of the tubular fluid conduits defines an opening extending between the exterior and the interior of the conduit. The connector may have an interior which is substantially accessible to the interior of the first tubular fluid conduit, and is also configured for annular enlargement. An expandable structure is provided having a first portion configured to annularly enlarge the connector by engaging the interior of the connector. In a preferred embodiment, a second portion of the expandable connector is configured to extend through the opening in the medial portion of the first tubular fluid conduit.
According to a preferred embodiment, a portion of the connector may be configured for attachment to the axial end of the first tubular fluid body conduit and be substantially coaxial therewith. The connector may include members having free end portions that are configured to penetrate the first tubular body conduit at locations that are axially spaced around the connector. An axial portion of the connector may be configured for insertion through an opening in a side wall of the second tubular fluid conduit. The connector may include members having free end portions that are directed radially outward and are configured to engage the exterior of the side wall of the second tubular fluid conduit when a predetermined axial portion of the connector has passed through the opening in the side wall of the second tubular fluid conduit.
In order to remotely expand the first, distal portion of the expandable structure, the expandable structure also includes a third, proximal portion for remotely introducing fluid or pressurized air. A tapered structure may be provided for dilating the opening in the second fluid tubular conduit by advancing the tapered structure through the opening. A longitudinal member may be provided which is configured to extend between the first tubular fluid conduit and the second tubular fluid conduit. In a preferred embodiment, the longitudinal member is configured to extend through the opening in the second tubular fluid conduit and along the lumen thereof. The tapered structure may also include an elongated tubular structure, e.g., a catheter-like structure, axially extending from an end portion of the tapered structure and coaxial with the longitudinal member. The tapered structure may be configured to be advanced into and along the interior of the second tubular fluid conduit after dilating the opening in the side wall thereof. Alternatively, the tapered structure is configured to be advanced into and along the interior of the first tubular fluid conduit after dilating the opening in the side wall of the second tubular body conduit. In such a case, the connector may have annularly expanded sufficiently to allow the tapered structure to pass through the interior of the connector. As an alternative or in addition to the tapered structure, a second expandable structure, such as a balloon, may be provided which is configured to dilate the opening in the second tubular fluid conduit.
Further in accordance with the invention, apparatus and methods are provided to make a second anastomotic connection between the first tubular fluid conduit and a third tubular fluid conduit. The first tubular fluid conduit defines first and second axial end portions. The apparatus further includes a second connector configured for attachment to the first and third tubular fluid conduits and having an interior thereof substantially accessible to the interior of the first tubular fluid conduit. The second connector is also configured for annular enlargement. A second expandable structure is provided having a first, distal portion configured to annularly enlarge the second connector by engaging the interior of the second connector, and having a portion configured to extend through the opening in the medial portion of the first tubular fluid conduit. The distal portion of the first expandable structure and the distal portion of the second expandable structure are independently and/or simultaneously expandable.
The first tubular fluid conduit may be a natural body conduit, such as the saphenous vein or the internal mammary artery, and the opening in a medial portion thereof may be a natural side branch. Alternatively, the first tubular fluid conduit may be an artificial graft conduit.
Further apparatus and methods for installing a tubular graft conduit between first and second spaced locations in a patient""s tubular body structure are disclosed. Apparatus in accordance with the invention may include first and second connectors attached to the axial ends of the tubular graft conduit and having interior portions substantially accessible to the interior of the tubular graft conduit. A first expandable structure may be provided having a first balloon portion for annularly expanding a portion of the first connector by engaging the interior of the first connector and a first elongated structure for remotely expanding the first balloon member. The first expandable structure may be provided with an axial opening extending therethrough. A second expandable structure may also be provided having a second balloon portion for annularly expanding a portion of the second connector by engaging the interior of the second connector and a second elongated structure for remotely expanding the second balloon member. A portion of the second expandable structure may extend coaxially through the axial opening in the first expandable structure.
A method of installing the tubular graft conduit between first and second spaced locations in a patient""s tubular body structure is disclosed, which includes providing an aperture through a wall of the tubular body structure at the first location with a distal portion of an elongated structure inserted into and along a lumen of the tubular body structure to the first location. A graft is provided having first and second connectors attached to axial ends of the graft.
The graft may be passed along the lumen of the tubular body structure through the wall at one of the first and second locations to the other of the locations. A further step may be to attach axial end portions of the graft to the tubular body structure adjacent the first and second locations by annularly expanding the first and second connectors. According to a preferred embodiment, the step of attaching axial end portions of the graft to the tubular body structure by annularly expanding the first and second connectors may be achieved by expanding first and second expandable structures positioned adjacent the interiors of the first and second connectors.
In accordance with a preferred embodiment, the step of attaching axial end portions of the graft to the tubular body structure may include annularly expanding a first axial portion of the first connector spaced furthest from the first location, inserting a second axial portion of the first connector into the tubular body structure at the first location such that the first axial portion of the first connector remains outside the tubular body structure, and annularly expanding the second axial portion of the first connector positioned inside the tubular body structure. In order to deploy the connector as described above, the method may include providing a second elongated structure having a lumen, coaxially positioned to surround an axial portion of the first connector. When the second elongated structure is provided in an embodiment in accordance with the invention, the first axial portion of the first connector may be exposed from the lumen of the second elongated structure while retaining the second axial portion within the lumen of the second elongated structure, before annularly expanding the first axial portion of the first connector. Moreover, before inserting a second axial portion of the first connector into the tubular body structure at the first location, the distal end portion of the first elongated structure may be retracted into the tubular body structure. In addition, before annularly expanding the second axial portion of the first connector positioned inside the tubular body structure at the first location, the second portion of the first connector may be exposed from the lumen of the second elongated structure.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.